title: Properties of rice stem extracts obtained by using subcritical fluids.
abstract: Rice stems were subjected to a subcritical fluid treatment at 230 °C, using ethanol or acetone at a dilution of 0-100% in water. The obtained extracts were determined for their yield, carbohydrate content, phenolic content, DPPH radical scavenging ability, and color. The highest yield and carbohydrate content were achieved with the subcritical 20% (v/v) organic solvent, while the highest phenolic content was obtained with subcritical 80% (v/v) acetone. The highest radical scavenging ability was achieved with subcritical 60% (v/v) ethanol and 80% (v/v) acetone. The lightness of the extracts obtained with subcritical ethanol and acetone was negatively correlation with their radical scavenging ability (R=-0.85). The relationship between the lightness and phenolic content of the extracts was not significant, suggesting that other substances in the extract could also possess radical scavenging ability.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University.
authors.forename: Boonnakhom
authors.initials: B
authors.lastname: Tangkhavanich
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Shuji
authors.initials: S
authors.lastname: Adachi
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D002241:Carbohydrates / Q000032:analysis; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification*; D012275:Oryza / Q000737:chemistry*; D019800:Phenol / Q000032:analysis; D010851:Picrates / Q000737:chemistry; D010858:Pigmentation; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification*; D018547:Plant Stems / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D002241:Carbohydrates; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D019800:Phenol; C004931:1,1-diphenyl-2-picrylhydrazyl